This training program in mechanisms of viral infection will train eight predoctoral students and four postdoctoral fellows per year. The goal of this training grant is to provide students who: 1) are well trained in the study of mechanisms of viral replication, 2) can investigate human viruses causing disease, such as the human immunodeficiency virus and herpes viruses, 3) can investigate new antiviral compounds and vaccines to prevent or treat viral diseases, 4) can study viruses that are potential agents of bioterrorism, and 5) can use viruses to probe the cellular and molecular biology of prokaryotic and eukaryotic cells. Nearly all of the predoctoral applicants will have an undergraduate education in biology or chemistry. All of the predoctoral trainees will be graduate students in the Program in Virology, and inter-faculty degree granting program. The laboratories of the training faculty are located at Harvard Medical School, Harvard School of Public Health, Dana-Farber Cancer Institute, Children's Hospital, New England Primate Research Center, and the Harvard University Fairchild Laboratory in Cambridge. The Program in Virology students will pursue a broad biological program of study with courses in virology, molecular biology and genetics, biochemistry, cell biology and immunology. These students will also attend seminars, research meetings, and perform two to three laboratory rotations. Faculty curriculum advisors will provide guidance for the students throughout their training, and they will choose their advisors from the Program in Virology faculty. Students will take their preliminary qualifying examination during their second year, and after their examination, a dissertation advisory committee will be formed to provide advice on the progress of their research. Upon successful completion and defense of the dissertation, the student will be awarded a PhD degree in virology. Postdoctoral trainees will be selected by the individual faculty members and approved by the program director. Nearly all of the postdoctoral trainees have the PhD degree, and formal courses will not be required, except for Responsible Conduct of Science. In addition to the research training, seminars, research meeting, mentoring meetings, and the extensive interactions between the virology laboratories will form an important part of the postdoctoral training program. Predoctoral and postdoctoral trainees will participate in a training program in the ethical conduct of science. An active and previously successful program by the training faculty and Division of Medical Sciences is described for the recruitment of underrepresented minority trainees.